A fuel-tank assembly for a motor vehicle usually is provided on its floor with a vessel from which the fuel is pumped to the engine. The fuel not consumed by the engine is recirculated by this pump back into the tank. This tank is provided internally with upright antislosh plates or baffles which prevent the fuel therein from moving excessively back and forth.
The disadvantage of this system is that the unused fuel that is reintroduced back into the tank is substantially warmer than the fuel already in the tank. If constantly recirculated, the fuel will very quickly rise to a high temperture decreasing the efficiency of the pump and increasing the possibility of a vapor blockage of further fuel feed.